One goal of this project is the development of syntheses of the oxindole alkaloids gelsemine, gelsevirine, and 21-oxogelsemine. This will be accomplished using methodology that revolves around free radical cyclizations of general interest to the area of alkaloid synthesis. A subgoal of this project is the preparation of gelsemine substructures to be submitted for evaluation as CNS agents. A second goal of this project is the development of an efficient synthesis of the tetracyclic alkaloid stenine. This research will examine the value of certain pericyclic and free radical reactions for the synthesis of Stemonaceae alkaloid substructures and serve as a prelude to the synthesis of the anthelminthic alkaloid tuberostemonine. The final objective of this project is to prove the structure of the dipeptide antibiotic alahopcin via total synthesis. The synthesis will be accomplished using a strategy that revolves around an enantioselective ester-imine condensation. An outgrowth of this project should be the development of a protocol for the production of alahopcin analogs. A subgoal of this project will be the evaluation of alahopcin substructures for antibiotic activity.